US4574811A - Pressure dome - Google Patents
Pressure dome Download PDFInfo
- Publication number
- US4574811A US4574811A US06/591,724 US59172484A US4574811A US 4574811 A US4574811 A US 4574811A US 59172484 A US59172484 A US 59172484A US 4574811 A US4574811 A US 4574811A
- Authority
- US
- United States
- Prior art keywords
- head
- tongue
- neck
- circular opening
- base
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
- G01L19/14—Housings
Definitions
- This invention relates to improvements in pressure domes used for coupling the blood pressure of a patient to a transducer that generates an electrical signal corresponding to the pressure.
- the domes are generally comprised of a body portion having ports extending therethrough so as to communicate with a cavity therein and a membrane that closes the open side of the cavity. Generally but not necessarily, the edge of the cavity to which the membrane is attached is circular.
- Use of the dome involves connecting a valve to a first port and connecting another valve between the second port and one end of a catheter. Both valves are opened and a suitable fluid is passed through the first port until both the cavity and the catheter are filled.
- the valve connected to the first port is then closed and the open end of the catheter is pushed through the arterial system until it reaches the point therein at which the pressure is to be measured.
- the dome is then attached to a pressure transducer in such manner that its membrane is brought into intimate contact with the pressure sensing surface of the transducer.
- the membrane of a pressure dome may be placed in contact with the pressure sensing surface of a transducer by screwing the dome and the transducer together, it was found that the contact pressure between the membrane and the pressure sensing surface of the transducer varied with the applied torque so as to require adjustment of the zero setting for each application.
- this problem was overcome by holding the dome and transducer together with a force determined by the tension of springs and arranging that the tension attain a given repeatable maximum value.
- accidental forces occurring during handling or increases in the pressure of the fluid in the dome cavity can force the dome away from the transducer so as to permanently damage the springs by flexing them too far and/or permanently deform the membrane.
- a preferred form of the invention involves an addition to the dome structure described in the previously mentioned patent to Tykulsky, U.S. Pat. No. 4,185,641.
- That dome is comprised of a base having a cavity with a circular opening that is covered by a membrane, two ports communicating with the cavity so that it can be filled with fluid as described, and an annular wall of greater diameter than the circular opening.
- the foot of the annular wall is attached to the base so that it is concentric with the circular opening and lies on the side of the membrane that is opposite the cavity.
- a plurality of openings are formed in the top of the wall, and apertures extending through the wall respectively communicate with each opening.
- each aperture starts at its opening and slopes gradually toward the membrane so as to form a ramp and then proceeds parallel to the membrane so as to form a flat section. If a detent notch is desired, the flat section is below the end of the ramp.
- the material of the annular wall between this edge of the aperture and the top of the wall thus forms a long thin tongue that is joined to the annulus at one end.
- Mechanical stops are respectively formed at the ends of the flat sections so as to limit rotation of pins following therealong.
- bridges are formed that respectively extend radially outward between the free ends of the tongues and the annulus so that the tongues are rigidly supported beam springs. If such bridges are not used, the tongues are cantilever springs.
- a transducer that is to be attached to the dome is provided with outwardly extending radial pins that are angularly displaced in the same manner as the openings in the top of the wall.
- the transducer When the pins are respectively placed in these openings and under the respective bridges, the transducer is coaxial with the annular wall and the circular opening of the cavity, and the pressure sensing surface of the transducer is in or nearly in contact with the membrane covering the circular opening.
- the pins ride up the respective ramp sections of the adjacent tongues so as to flex the tongues more and more in an axial direction away from the membrane and thus increase the force with which the pressure sensing surface pushes against the membrane.
- the force is at its maximum value and does not increase with further rotation because the pins merely slide along the flat sections of the tongues and parallel to the membrane until they strike the stops.
- a stop means having a head a and neck is molded from the material of the annular wall with its neck attached to the flat section of the tongue.
- the neck may serve as the mechanical stop for the pins previously referred to.
- the stop means extends toward the membrane.
- An opening is formed in the material of the annular wall having a head portion surrounding the head of the stop means and a neck portion through which the neck of the stop means passes. There is a gap between the point where the head of the stop joins its neck and the point where the head portion of the opening joins its neck portion. As the tongue is bent away from the membrane, the gap gets smaller on the side toward the tongue.
- the stop means may have the shape of a "T", an "L” or a lollipop, all of which have head and neck portions.
- FIG. 1 is a bottom view of a pressure dome incorporating the invention showing the membrane and annular wall;
- FIG. 1A is a cross-section AA of FIG. 1;
- FIG. 2 is a projection view showing the bottom of a pressure dome incorporating this invention
- FIG. 3 is a projection view of a transducer housing oriented approximately as it would be when it is to be attached to the dome of FIG. 2;
- FIG. 4 is view like FIG. 3 taken from a slightly different angle
- FIG. 4A is a top view of the pressure dome.
- an annular wall 2 resting on a base B forms a cavity C that is covered by a transparent membrane M.
- Ports 4 and 6 in the base B communicate with the cavity C and are connected to passageways 4' and 6' contained within the base B and tubes 4" and 6" that can be connected to valves, as previously described.
- an opening O' is formed in the annular wall W.
- the edge of the opening O' that is farther away from the membrane M in an axial direction and the top of the wall W form between them the tongue T having an inner end at 8 and an outer end at 10. The latter would be free except for the bridge b.
- the bridge b joins the end 10 to the wall W in such manner as to leave the opening O between the end 10 of the tongue T and the top of the wall W.
- the purpose of the bridge b is to strengthen the tongue T, but the tongue T acts as a beam spring.
- a ramp R on the tongue T that is adjacent to the opening O slopes toward the membrane M and is joined via a detent notch 11 to a flat section F that is parallel to the membrane M.
- a stem 12 of a T-shaped stop is joined to the tongue T at an intermediate point on the flat section F. The stop extends toward the membrane M and fits inside a T-shaped opening O" formed in the annular wall W and a portion 13 of the base B. If the annular wall W were higher, the portion 13 would not be necessary and the opening O" could lie entirely within the wall W.
- FIG. 3 illustrates one form of a housing 14 for a transducer that is designed for coupling to the pressure dome.
- the pressure sensor itself is not shown but is circular and fits snugly in the cavity C' with its pressure sensing surface in the plane of the top of the cavity.
- the housing 14 is provided with pins 16 and 18 that extend perpendicularly from the axis of the cavity C' and are diametrically opposed so that when the axis of the cavity C' is aligned with the axis of the cavity C, the pins 16 and 18 can be respectively inserted under the bridges b into the openings 0 in the top of the annular wall W.
- Rotation of the housing 14 will cause its pins 16 and 18 to ride up the respectively adjacent ramps R so as to flex the tongues T away from the membrane M and increase the force with which the pressure sensing surface of the transducer bears against the membrane M.
- the pins 16 and 18 drop over the notches 11 and reach the flat sections F, further rotation does not increase the force and further rotation is prevented by the pins 16 and 18 coming into contact with the stem 12 of the T-shaped stop.
- diametrically opposed tabs 20 and 22 are provided that extend radially outward from the top of the wall W at points that are angularly midway between the flat sections F on the tongues. As the housing 14 is axially rotated and the pins 16 and 18 are riding up the ramps R of the tongues, the tabs 20 and 22 respectively slide under L-shaped brackets 20' and 22' and will prevent the dome from being rocked about an axis between the pins 16 and 18.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
Description
Claims (4)
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/591,724 US4574811A (en) | 1984-03-21 | 1984-03-21 | Pressure dome |
DE3509509A DE3509509C2 (en) | 1984-03-21 | 1985-03-16 | Pressure measuring capsule |
DE8507805U DE8507805U1 (en) | 1984-03-21 | 1985-03-16 | Pressure measuring capsule |
JP1985041018U JPS60153102U (en) | 1984-03-21 | 1985-03-20 | Pressure dome for blood pressure measurement |
FR858504191A FR2561513B1 (en) | 1984-03-21 | 1985-03-21 | PRESSURE TRANSMISSION COUPLING, PARTICULARLY FOR TRANSMISSION OF BLOOD PRESSURE FROM A PATIENT TO A TRANSDUCER |
GB08507395A GB2156081B (en) | 1984-03-21 | 1985-03-21 | Pressure dome |
JP1065761A JPH021219A (en) | 1984-03-21 | 1989-03-17 | Pressure dome for measuring blood pressure |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/591,724 US4574811A (en) | 1984-03-21 | 1984-03-21 | Pressure dome |
Publications (1)
Publication Number | Publication Date |
---|---|
US4574811A true US4574811A (en) | 1986-03-11 |
Family
ID=24367645
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/591,724 Expired - Lifetime US4574811A (en) | 1984-03-21 | 1984-03-21 | Pressure dome |
Country Status (5)
Country | Link |
---|---|
US (1) | US4574811A (en) |
JP (2) | JPS60153102U (en) |
DE (2) | DE8507805U1 (en) |
FR (1) | FR2561513B1 (en) |
GB (1) | GB2156081B (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5417395A (en) * | 1993-06-30 | 1995-05-23 | Medex, Inc. | Modular interconnecting component support plate |
US5752918A (en) * | 1993-06-30 | 1998-05-19 | Medex, Inc. | Modular medical pressure transducer |
US5868678A (en) * | 1993-06-30 | 1999-02-09 | Medex, Inc. | Two-part medical pressure transducer with diaphragm stand-offs |
US20090071258A1 (en) * | 2006-04-19 | 2009-03-19 | Asahi Kasei Kuraray Medical Co., Ltd. | Pressure sensor for extracorporeal circulating circuit |
US20150338302A1 (en) * | 2010-04-30 | 2015-11-26 | Fresenius Medical Care Deutschland Gmbh | Membrane for a pressure dome |
US11035748B2 (en) * | 2016-08-03 | 2021-06-15 | Nidec Tosok Corporation | Pressure sensor attachment structure |
US11408788B2 (en) * | 2020-03-31 | 2022-08-09 | Toyota Research Institute, Inc. | Variable geometry and stiffness control for fluid filled sensor |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4948991A (en) * | 1988-11-03 | 1990-08-14 | Motorola Inc. | Load controlled ECL transient driver |
DE3918142A1 (en) * | 1989-05-31 | 1990-12-13 | Wiest Peter P | PRESSURE MEASURING DEVICE FOR FLUIDS FLOWING IN LINE |
GB9509576D0 (en) * | 1995-05-11 | 1995-07-05 | Sydney Smith Dennis Limited | Case for an analogue instrument |
WO2003055591A1 (en) | 2001-12-25 | 2003-07-10 | Wellness Co., Ltd. | Field converter and fluid processing device using the converter |
JP2008051663A (en) * | 2006-08-24 | 2008-03-06 | Asahi Kasei Kuraray Medical Co Ltd | Pressure sensor |
JP2008259553A (en) * | 2007-04-10 | 2008-10-30 | Asahi Kasei Kuraray Medical Co Ltd | Pressure sensor |
CN110657916B (en) * | 2019-10-15 | 2021-06-01 | 天长市旭升热工仪表配件有限公司 | Pressure instrument reinforcing protection device |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4185641A (en) * | 1978-08-23 | 1980-01-29 | Hewlett-Packard Company | Pressure dome |
US4398542A (en) * | 1980-12-15 | 1983-08-16 | Ivac Corporation | Pressure diaphragm |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB574395A (en) * | 1942-12-05 | 1946-01-03 | Bendix Aviat Corp | Containers with open ends closable by covers, for example instrument cases |
-
1984
- 1984-03-21 US US06/591,724 patent/US4574811A/en not_active Expired - Lifetime
-
1985
- 1985-03-16 DE DE8507805U patent/DE8507805U1/en not_active Expired
- 1985-03-16 DE DE3509509A patent/DE3509509C2/en not_active Expired
- 1985-03-20 JP JP1985041018U patent/JPS60153102U/en active Pending
- 1985-03-21 FR FR858504191A patent/FR2561513B1/en not_active Expired - Fee Related
- 1985-03-21 GB GB08507395A patent/GB2156081B/en not_active Expired
-
1989
- 1989-03-17 JP JP1065761A patent/JPH021219A/en active Granted
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4185641A (en) * | 1978-08-23 | 1980-01-29 | Hewlett-Packard Company | Pressure dome |
US4398542A (en) * | 1980-12-15 | 1983-08-16 | Ivac Corporation | Pressure diaphragm |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5417395A (en) * | 1993-06-30 | 1995-05-23 | Medex, Inc. | Modular interconnecting component support plate |
US5752918A (en) * | 1993-06-30 | 1998-05-19 | Medex, Inc. | Modular medical pressure transducer |
US5848971A (en) * | 1993-06-30 | 1998-12-15 | Medex, Inc. | Modular medical pressure transducer |
US5868678A (en) * | 1993-06-30 | 1999-02-09 | Medex, Inc. | Two-part medical pressure transducer with diaphragm stand-offs |
US20090071258A1 (en) * | 2006-04-19 | 2009-03-19 | Asahi Kasei Kuraray Medical Co., Ltd. | Pressure sensor for extracorporeal circulating circuit |
US7748275B2 (en) | 2006-04-19 | 2010-07-06 | Asahi Kasei Kuraray Medical Co., Ltd. | Pressure sensor for extracorporeal circulating circuit |
US20150338302A1 (en) * | 2010-04-30 | 2015-11-26 | Fresenius Medical Care Deutschland Gmbh | Membrane for a pressure dome |
US9435706B2 (en) * | 2010-04-30 | 2016-09-06 | Fresenius Medical Care Deutschland Gmbh | Membrane for a pressure dome |
US11035748B2 (en) * | 2016-08-03 | 2021-06-15 | Nidec Tosok Corporation | Pressure sensor attachment structure |
US11408788B2 (en) * | 2020-03-31 | 2022-08-09 | Toyota Research Institute, Inc. | Variable geometry and stiffness control for fluid filled sensor |
Also Published As
Publication number | Publication date |
---|---|
JPH021219A (en) | 1990-01-05 |
DE3509509C2 (en) | 1987-05-07 |
FR2561513B1 (en) | 1994-03-04 |
JPH0513661B2 (en) | 1993-02-23 |
DE8507805U1 (en) | 1985-04-25 |
GB2156081A (en) | 1985-10-02 |
FR2561513A1 (en) | 1985-09-27 |
GB2156081B (en) | 1988-02-10 |
DE3509509A1 (en) | 1985-09-26 |
JPS60153102U (en) | 1985-10-12 |
GB8507395D0 (en) | 1985-05-01 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: HEWLETT-PACKARD COMPANY, PALO ALTO, CA., A CORP. O Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STEPHENS, THOMAS P.;REEL/FRAME:004479/0958 Effective date: 19840315 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
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FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |
|
AS | Assignment |
Owner name: HEWLETT-PACKARD COMPANY, A DELAWARE CORPORATION, C Free format text: MERGER;ASSIGNOR:HEWLETT-PACKARD COMPANY, A CALIFORNIA CORPORATION;REEL/FRAME:010841/0649 Effective date: 19980520 |
|
AS | Assignment |
Owner name: AGILENT TECHNOLOGIES INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY, A DELAWARE CORPORATION;REEL/FRAME:010901/0336 Effective date: 20000520 |
|
AS | Assignment |
Owner name: KONINKLIJKE PHILIPS ELECTRONICS N.V., NETHERLANDS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AGILENT TECHNOLOGIES, INC.;REEL/FRAME:014662/0179 Effective date: 20010801 |
|
AS | Assignment |
Owner name: KONINKLIJKE PHILIPS ELECTRONICS N V, NETHERLANDS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AGILENT TECHNOLOGIES, INC.;REEL/FRAME:022835/0572 Effective date: 20090610 |